Cell Biology

• What is the basic unit of all forms of life?

  Cells
• How do structural differences between cells affect their functions?

  They enable cells to perform specific functions
• What controls the differences in cells?

  Genes in the nucleus
• What process do cells undergo to grow?

  Cell division by mitosis
• What happens if cells are isolated at an early growth stage?

  They can grow into different cell types
• What technology has developed from the ability of early-stage cells to differentiate?

  Stem cell technology
• What do plant and animal cells have in common?

  Cell membrane, cytoplasm, nucleus
• What is a key difference between prokaryotic and eukaryotic cells?

  Prokaryotes lack a nucleus
• What is the genetic material structure in bacterial cells?

  A single DNA loop and plasmids
• What are the main parts of most animal cells?

  Nucleus, cytoplasm, cell membrane, mitochondria, ribosomes
• What additional parts do plant cells have compared to animal cells?

  Cell wall, Chloroplasts and a permanent vacuole
• What strengthens plant cells?

  Cell wall made of cellulose
• Why is it important to estimate sizes of sub-cellular structures?

  To judge their relative size or area
• What is cell specialization?

  Cells adapting to perform specific functions
• Name three specialized animal cells.

  Sperm cells, nerve cells, muscle cells
• Name three specialized plant cells.

  Root hair cells, xylem, phloem
• What is the importance of cell differentiation?

  It allows formation of different cell types
• How do most animal cells differentiate?

  At an early stage of development
• How do many plant cells differentiate?

  They retain the ability to differentiate throughout life
• What is the role of mitosis in multicellular organisms?

  Growth and development
• What do chromosomes contain?

  DNA molecules
• How are chromosomes arranged in body cells?

  Normally found in pairs
• What is the cell cycle?

  A series of stages for cell division
• What happens to genetic material during the cell cycle?

  It is doubled and then divided
• What must a cell do before it divides?

  Grow and increase sub-cellular structures
• What occurs during mitosis? (stages 3marks)

  1. DNA is Duplicated to form two copies of each chromosome.
  2. Then Organelles increase in size.
  3. Afterwards one set of chromosome is pulled to each end of the cell and the nucleus divides.
  4. Finally the cytoplasm and the cell membranes divide to form two identical cells.
• What is the final step of cell division?

  Division of cytoplasm and cell membranes
• What is a stem cell?

  An undifferentiated cell capable of differentiation
• What can stem cells from human embryos do?

  Differentiate into most human cell types
• What can stem cells from adult bone marrow form?

  Many types of cells including blood cells
• What is the role of meristem tissue in plants?

  Differentiate into any type of plant cell
• What is therapeutic cloning?

  Producing an embryo with the same genes as the patient
• What are potential risks of stem cell treatment?

  Transfer of viral infection
• What are some ethical concerns regarding stem cells?

  Objections based on ethical or religious beliefs
• How can stem cells from meristems benefit agriculture?

  Produce clones quickly and economically
• What is osmosis?

  Diffusion of water through a membrane
• What is required for active transport?

  Energy from respiration
• How does active transport benefit plants?

  Allows absorption of mineral ions from soil
• How does active transport help in the gut?

  Absorbs sugar molecules into the blood
• What is diffusion?

  Movement from high to low concentration